1. Field
Example embodiments relate to a semiconductor device and/or a method of manufacturing the same, and for example, to a thin film transistor and/or a method of manufacturing the same.
2. Description of Related Art
Thin film transistors (TFTs) are used as switching devices in flat panel display apparatuses, for example, a liquid crystal display apparatus or an organic light emitting display apparatus. The mobility or leakage current of the TFTs is greatly affected by the material and the state of a channel layer of the TFT.
In commercially produced liquid crystal display apparatuses, the channel layer of the TFT is mainly an amorphous silicon layer which has a charge mobility of approximately 0.5 cm2/Vs, which is relatively very low. Therefore, increasing the operation speed of the commercially produced liquid crystal display apparatuses is more difficult.
Accordingly, research has been conducted on using an oxide semiconductor material layer as the channel layer of the TFT, for example, a ZnO based material layer, having a charge mobility higher than that of the amorphous silicon layer. A Ga—In—Zn—O layer, which is one of the ZnO based material layers, has a charge mobility tens of times greater than the amorphous silicon layer. Therefore, TFTs that use the Ga—In—Zn—O layer as the channel layer are expected to be the next generation driving devices of display apparatuses.
However, if the ZnO based material layer is employed as the channel layer of a TFT, the channel may be damaged after the channel layer is formed, and as a result, the electrical characteristics of a device may degrade.